He went to Y Combinator selling software to contractors. Then he decided to become one.
Casey Bell runs a construction company the way most people run a software startup. Daily-updating schedules. Photo logs every week. Pricing in hours, not weeks.
Walk onto an Aecore jobsite and the drywall looks like drywall, the conduit looks like conduit, and the framing looks like framing. What you cannot see from the floor is the part Casey Bell cares about most: the back office isn't drowning in paper, the schedule updated itself almost overnight, and the client already saw a 360-degree walkthrough of their own building without leaving their desk. That is the whole pitch. Bell is the co-founder and CEO of Aecore, a commercial general contractor in San Jose, California that builds office interiors, life sciences facilities, R&D centers, and retail spaces - and that runs its own proprietary software instead of buying whatever the industry was using in 2003.
Aecore calls itself a technology-enabled commercial contractor focused on vertical integration and agile project delivery through automation. Translated out of startup language: design, project management, and software engineering all live under one roof, and they guide a client from the first sketch to the final punch list. It is an unusual sentence to read about a general contractor. That is exactly the point.
Here is the part that sounds made up. Bell and his co-founder, Anthony Cirinelli, did not set out to swing hammers. They went through Y Combinator's Summer 2017 batch with a company called Net30 - a tool to streamline invoicing and payments for construction projects. Clean idea. Real problem. Bell had felt the pain himself as a project manager.
Then they actually talked to their customers. Small and mid-sized general contractors weren't just bad at payments. They were running everything - scheduling, documentation, pricing, the lot - on systems that belonged in a filing cabinet. Selling one piece of software into that mess felt like handing someone a faster horse. So they made a stranger bet. Instead of selling tools to contractors, they would become the contractor, and bake the technology in from the first day. As Bell put it: "build a construction company with technology at its core from day one." Net30 became Aecore. The code stayed. The business model flipped entirely.
The innovations are refreshingly unglamorous, which is how you know they matter. Aecore automated the back-office tasks that bury most contractors in paperwork. It put 360-degree photo documentation on a weekly cadence, so a client in another city can see exactly what got built and when. It built dynamic scheduling that updates almost daily instead of living as a stale PDF nobody trusts. And it developed rapid rough-order-of-magnitude pricing, so a client gets a number while the idea is still warm.
None of this is flashy. None of it photographs well. But anyone who has waited three weeks for a budget estimate or argued over who changed the schedule understands why a contractor that fixes those specific things is worth writing about.
"This isn't just about building better buildings. It's about building a better way to build."
The reason the software bet works is that Bell didn't parachute into construction from a coding bootcamp. He spent years on the other side of the problem. From 2012 to 2016 he was a project manager at Turner Construction Company - one of the largest builders in the country - with earlier stops at McCarthy Building Companies and Floortec. He studied at UC Berkeley. By the time he co-founded Net30 in 2016, he had felt every inefficiency he later set out to kill.
That sequence matters. Plenty of people have opinions about how construction should be modernized. Far fewer have stood on a jobsite at 6 a.m. trying to reconcile a schedule that three subcontractors each remember differently. Bell did the second thing first. Aecore is what he built once he had the standing to argue the industry was stuck.
There's a tell in the company's own framing - the line about combining exceptional people with proprietary software, with relentless attention to detail and a commitment to disrupting the status quo. It reads like a software manifesto. It describes a general contractor. Bell seems to enjoy that collision.
An illustrative read on the pain points Aecore set out to automate away - the unglamorous stuff that decides whether a project runs clean.
Small, true, slightly odd things that don't fit the headline.
Aecore's Y Combinator entry is still filed under its codename, "X3 Builders."
The pivot kept the technology and threw out the business model. Net30 the payments app quietly became Aecore the contractor.
One company, two metros - San Jose to Nashville - testing whether a tech-first contractor travels.
It runs its own proprietary software stack rather than buying whatever the industry settled for.
"Build a construction company with technology at its core from day one."
The bet underneath the company is simple and a little audacious: a builder designed around software can be faster, clearer, and more honest than a builder that treats software as an afterthought.
Bell's aim isn't to sell the industry a better tool. It's to prove the model by living inside it - delivering market-ready office, lab, and retail spaces while the proprietary software quietly does the coordinating. Then scale that model past Silicon Valley, which is what the Nashville expansion is really testing.
If he's right, the interesting outcome isn't a slicker app. It's a contractor that competitors have to copy. That's a longer game than a payments startup, and a stranger one for a Y Combinator founder to choose. Bell chose it anyway.
A field-tested project manager who turned a failed-pitch payments app into a contractor that argues, in working code, that there is a better way to build.